Promote performance knowledge from community to Microsoft layer (#50)

Pure git-mv relocation of all 7 performance articles from community/knowledge/performance/ to microsoft/knowledge/performance/. No content changes.

Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

microsoft/knowledge/performance/avoid-growing-globals-in-singleinstance-subscribers.bad.al

@@ -0,0 +1,16 @@
+codeunit 50100 "Event Audit Buffer"
+{
+    SingleInstance = true;
+
+    // Unbounded global: every event fires adds an entry for the lifetime of the session.
+    var
+        AllEventIds: List of [Guid];
+
+    [EventSubscriber(ObjectType::Table, Database::"Sales Header", OnAfterInsertEvent, '', false, false)]
+    local procedure OnAfterInsertSalesHeader(var Rec: Record "Sales Header")
+    begin
+        // No cap. No eviction. No reset. A session that sees ten thousand inserts
+        // keeps ten thousand GUIDs in memory until the user signs out.
+        AllEventIds.Add(Rec.SystemId);
+    end;
+}